I have a Denon Audio Video Receiver hooked up to my WiFi network.
I can "see" it from my Windows Phone, and from Windows Media Player. If I use the Denon controls, I can see my music collection on my laptop and can play files via DLNA.
Since the XBox Music App for Windows 8.1 is so kick-*ss, I'd love to be able to play files from it directly to the Denon, but the Denon does not appear in the Devices charm when accessed from XBox Music.
I do have the Denon AVR-1913 visible in the main Devices charm, it is recognized by Windows 8.1 however it is listed as "Not Windows Certified" - I believe this may be the cause of the issue.